This invention relates to a novel polymer, usage of the polymer, and a silver halide photographic photosensitive material using the polymer.
Various polymers having sulfate in molecule have been provided. For example, Japanese Unexamined Patent Publication (KOKAI) Heisei, No. 6-199,557, describes a sulfate as an additional compound of p-vinyl phenol polymer ethylene oxide is used for a builder for cements. Japanese Unexamined Patent Publication (KOAI) Showa, No. 53-39,119 describes a silver halide photographic photosensitive material containing polyvinylbenzene alkylsulfate. Also, Japanese Unexamined Patent Publication (KOKAI) Showa, No. 49-66,580 describes a sulfate of polyvinylphenol as a polymer conductivity controlling agent. Polystyrene sulfate, in addition to these materials, has been set forth in many patent specifications.
Where the above polymer is used as a dispersant, there raise problems that the particle size of a dispersed solid does not become so small, that the liquid dispersion cannot be handled easily due to the very high viscosity, and that precipitation and aggregation occur where the liquid dispersion has a bad stability. Where the polymer is mixed with hydrophilic colloids, there raise problems such that aggregation occurs or that the absorption spectrum of a coating film containing dyes is broadened.
It is an object of the invention to provide a novel polymer suppressing those problems. It is another object of the invention to develop usage of the polymer, more specifically to provide a dispersant not suffering from lowered surface tension when fine solid particles are dispersed, with improved dispersing property and improved dispersion stability. It is a further object of the invention to provide a silver halide photographic photosensitive material having good color reproductivity and improving storability before use and latent image storability at the same tome.
The foregoing objects are accomplished by the invention to provide a polymer comprising a repeating unit represented by formula (I): 
wherein K represents an alkylene group; M represents a monovalent cation group. In formula (I), K is preferably an alkylene group having 1 to 50 carbon atoms, more preferably, an alkylene group having 1 to 50 carbon atoms, and further preferably, a propylene group or a butylene group. The weight-averaged molecular weight of the invented polymer is preferably of 103 to 106, and the polymer consists solely of the repeating unit, or comprises 95 mol % or less of a repeating unit derived from ethylenic unsaturated monomers capable of copolymerizing other than the repeating unit represented by formula (I), in addition to repeating unit represented by formula (I). As an ethylenic unsaturated monomer capable of copolymerizing, exemplified are the group consisting of styrene, styrene derivatives, acrylic acid, acrylic acid derivatives, methacrylic acid, and methacrylic acid derivatives.
This invention further provides a silver halide photographic photosensitive material having at least one layer containing photosensitive silver halide, comprising the polymer comprising a repeating unit represented by formula (I). Particularly, this invention provides a silver halide photographic photosensitive material having, on a support, at least one layer containing photosensitive silver halide, and at least one layer including water-insoluble photographic solid grains formed on the support, wherein the water-insoluble photographic solid grains are dispersed as fine grains by the polymer comprising a repeating unit represented by formula (I) as a dispersant. As a water-insoluble photographic useful solid grains, exemplified is a dye compound represented by formula (II): 
wherein A represents an acidic nucleus; L1, L2, L3 each independently represents a methine group which can be substituted; R1, R2, and R3 each independently represents a hydrogen atom or a substituent; n denotes 0 or 1; m denotes an integer from 0 to 4; a plurality of R2 can be the same to or the different from one another when m denotes an integer of 2 to 4; X denotes an electron withdrawing group having a Hammett""s sigma value "sgr"m of 0.3 to 1.5.
This invention also provides a method for dispersing water-insoluble solid grains, particularly, solid grains for silver halide photographic photosensitive material, as fine grains using the dispersant containing the polymer comprising a repeating unit represented by formula (I).
It is to be noted that in this specification, a range includes the upper limit and the lower limit as within the range.
Hereinafter, this invention is described in detail.
The polymer of the invention includes a repeating unit represented by formula (I). In formula (I), K represents an alkylene group. More specifically, an alkylene group having 1 to 50 carbon atoms. Those alkylene group may be substituted.
The K, inter alia, preferably represents an alkylene group having 1 to 5 carbon atoms. More specifically, ethylene group, propylene group, butylenes group, and hexylene group can be exemplified. The K is more preferably a propylene group or butylene group.
In formula (I), M represents monovalent cation group. More specifically, cations such as hydrogen, sodium, potassium, lithium, ammonium, and the like can be exemplified. Sodium cation, inter alia, is most preferable.
The weight-averaged molecular weight of the polymer according to the invention is preferably of 103 to 106, more preferably 103 to 105, and further preferably 3xc3x97103 to 3xc3x97104.
The polymer according to the invention can be a homopolymer or copolymer solely containing one type or two or more types of the repeating unit represented by formula (I), or can be a copolymer including the repeating unit represented by formula (I), and a 95 mol % or less of a repeating unit derived from ethylenic unsaturated monomers capable of copolymerizing other than the repeating unit represented by formula (I).
As an ethylenic unsaturated monomer capable of copolymerizing other than the repeating unit represented by formula (I), exemplified are one type or two or more types of monomers selected from the group consisting of styrene, styrene derivatives, acrylic acid, acrylic acid derivatives, methacrylic acid, and methacrylic acid derivatives.
As a styrene derivative, vinyl toluene, hydroxystyrene, acyloxystyrene, alkoxystryrene, halogenated styrene, vinylbenzene carboxylic acid and salts and acids thereof are preferable. As an acyloxystyrene, acetoxystyrene is preferable. As an alkoxystryrene, t-butoxystyrene is preferable. As a halogenated styrene, bromostyrene and chlorostyrene are preferable.
As an acrylic acid derivative or methacrylic acid derivative, alkyl acrylate, alkyl methacrylate, cycloalkyl acrylate, cycloalkyl methacrylate, acrylic salt, methacrylic salt, and acrylonitrile are preferable.
Among those, styrene, vinyl toluene, hydroxystyrene, vinylbenzene carboxylic acid and salts thereof, alkyl acrylate, alkyl methacrylate, cycloalkyl methacrylate, and acrylonitrile are preferable.
Where the polymer of the invention is a copolymer including a repeating unit derived from an ethylenic unsaturated monomer, which is capable of copolymerizing other than the repeating unit represented by formula (I). The repeating unit derived from an ethylenic unsaturated monomer, capable of copolymerizing other than the repeating unit represented by formula (I), is present in an amount, in all the polymer, of 95 mol % or less, more preferably 85 mol % or less, and further preferably, 80 mol % or less.
The polymer of the invention can be manufactured by, e.g., the following two methods. The first method is to synthesize monomers introduced with sulfonic acid group and then solely polymerizing the monomer or co-polymerizing the monomers; the second method is to introduce sulfonic acid group by polymer reactions after a homopolymer or copolymer is obtained by sole polymerization, or copolymerization of vinyl phenol or monomers in which hydroxyl group of vinyl phenol is protected. The synthetic method according to the purpose.
[The First Method]
With respect to introduction of the sulfonic acid group, methods set forth in Kogyo Kagaku (Magazine) Vol. 73, 563 (1970), Vol. 59, 221 (1956), and J. Am. Chem. Soc. Vol. 77, 2496 (1955) can be referred.
When the monomers to which sulfonic acid group is introduced are polymerized solely or copolymerized, it is preferable to make polymerization by a radical polymerization method. In a copolymerization of monomers having sulfonic acid group and other monomers, a polymerization solvent can be a single base solvent such as methyl sulfoxide (DMSO), dimethyl formamide (DMF), and a mixture base solvent such as DMF and water (for example, a ratio of 8 to 2 (DMF to water) by volume).
[The Second Method]
When a vinyl phenol is polymerized solely or copolymerized, methods set forth in J. Polym. Sci. A-1 Vol. 7, 2175 (1969), 2405 (1969) can be referred. The homopolymer or copolymer of vinyl phenol can be polymerized from monomers commercially available or can be made using a polymer or polymers commercially available.
When monomers in which hydroxyl group of vinyl phenol is protected are polymerized solely or copolymerized, a well known protective group such as methyl group, t-butyl group can be used. As a monomer where the hydroxyl group of the vinyl phenol is protected, methoxystyrene, t-butoxystyrene, and the like can be exemplified. The sole polymerization or copolymerization of the monomers in which hydroxyl group of vinyl phenol is protected can be proceeded by any of a radical polymerization method, an anion polymerization method, and cation polymerization method. In this situation, living polymerization or the like can be used, and in the case of copolymerization, block polymers can be synthesized. Thereafter, the protective group of the hydroxyl group can be deprotected in an ordinary manner. For example, deprotection can be proceeded easily with boron tribromide, bromic acid, trifluoromethane sulfuric acid, and the like. Regarding deprotection of protective groups, Macromolecules, Vol. 16, 510 (1983), Vol. 22, 509 (1989) can be referred.
Subsequently, the sulfonic acid group is introduced utilizing the hydroxyl group. For introduction of the sulfonic acid group, a Williamson ether synthetic method can be used. That is, after the hydroxyl group is converted to a phenolate anion by sodium methylate, sodium ethylate, potassium t-butoxide, sodium hydroxyl, sodium metal, and the like, the sulfonic acid group can be introduced by.dropping addition of propane sultone, butane sultone, or sulfoalkyl halide such as chloroethane sodium sulfate. Where the introduction rate of the sulfonic acid group is set about 50 mol % or less, it can be introduced in a quantitative manner. If the introduction rate of the sulfonic acid group is set about 50 mol % or more, a slightly excessive reagent (e.g., about 1.2 time of the equivalent) is used. The reaction temperature is preferably at room temperature or higher, more preferably 45xc2x0 C. to 70xc2x0 C., further preferably around 60xc2x0 C. The reaction time, though depending on the reaction temperature, is about several hours (two to five hours), and a mild proceeding is preferred. With respect to introduction of sulfonic acid, methods set forth in Kogyo Kagaku (Magazine) Vol. 73, 563 (1970), Vol. 59, 221 (1956), and J. Am. Chem. Soc. Vol. 77, 2496 (1955) can be referred.
Specific examples of the polymer according to the invention are described below. The weight-averaged molecular weight can be measured in a normal way. 
The polymer according to the invention is useful as a dispersant. This polymer can also be used as antistatic agent, a thickener, and a precipitant. Those dispersant, antistatic agent, thickener, and precipitant may contain one type of the invented polymer or may contain two types or more at an arbitrary rate. Other components may be contained as appropriate.
For example, a dispersant may contain another dispersant or other dispersants in addition to the invented polymer. The use amount of the invented dispersant is preferably 1 to 100% by weight to the material to be dispersed, more preferably 20 to 30% by weight. The dispersant according to the invention can be used for various dispersion systems such as solid dispersion, emulsion dispersion, deposition dispersion, and the like.
As a method for rendering a material to be dispersed subjecting to solid dispersion using the dispersant according to the invention, known methods can be used. Details of such a solid dispersion method are described in xe2x80x9cRinousei Ganryo no Ohyou Gijyutu (Applied Techniques of Functional Pigments)xe2x80x9d Published by CMC (1991). A dispersion media method, among those, is most general. In this method, the materials to be dispersed in a form of powders or in a wet cake form are made into an aqueous slurry in water together with the dispersant of the invention, using a known mill (e.g., ball mill, sand mill, roller mill, super apex mill, or spike mill), where dispersion media (e.g., glass beads, alumina beads, zirconia beads, and the like) exist, dispersion is made by grinding mechanically the materials. The average diameter of the beads as the dispersion media is preferably 0.005 to 1 mm, more preferably 0.1 to 0.5 mm, further preferably 0.1 to 0.3 mm. The filling rate is preferably 70% or higher, more preferably 80% or higher. Circumferential speed is preferably 4m/second or more, more preferably 8 m/second or more, furthermore preferably 10 m/second or more. The temperature is preferably at 100xc2x0 C. or less, more preferably 40xc2x0 C. or less. The work density is preferably 0.5 kw/liter or higher as per real volume of dispersion chamber, more preferably 2 kw/liter or higher. In addition to the above mills, a roller mill, a homogenizer, a high pressure homogenizer, a colloid mill, a dissolver, a high speed impeller agitator, an ultrasound dispersing apparatus (e.g., micro-fuldizer) can be used.
As other solid dispersing methods, exemplified are, for example, as described in Japanese Unexamined Patent Publication Heisei No. 3-182,743, a method in which after materials to be dispersed are solved in water by adjusting the pH of the materials to be dispersed to be normally alkaline upon selection of substituents, the pH is lowered under existence of the invented dispersant to obtain the fine solid positioned, dispersed materials, and, as disclosed in U.S. Pat No. 2,870,012, a method in which after the materials are dissolved in an appropriate solvent, a poor solvent of the materials to be dispersed is added under existence of the invented dispersant to deposit the dispersed materials thereby obtaining fine particle dispersed solid.
Where the invented dispersant is used for solid dispersion, a low molecular surfactant can be used together, but the low molecular surfactant may lower the surface tension, thereby impairing coating property of the materials to be dispersed. In a case where the materials to be dispersed are photographic materials in which the materials to be dispersed migrate in a diffusing manner in the hydrophilic colloid layer, it is foreseeable that a problem that such migrations adversely affects the photographic property may occur, so that a use amount of the surfactant should be carefully determined. When a low molecular surfactant is used together, the use amount is preferably 50% by weight or lower with respect to the polymer including the repeating unit represented by formula (I) in the invented dispersant, more preferably 20% by weight or lower, and further preferably 10% by weight or lower.
As examples of the materials to be dispersed usable for the dispersant of the invention, exemplified are a dye image forming coupler, a color mixing prevention agent, a dye-providing redox compound, a fog-preventing agent, a reducing agent, an ultraviolet absorbing agent, a anti-fading agent, a nucleation agent, a dye image stabilizing agent, a silver halide solvent, a bleaching promoting agent, dyes for filter and those precursors, organic or inorganic compounds such as dyes, pigments, organic silver salt, silica, TiO2, zinc oxide, iron oxide, inorganic pigments such as carbon black (micro powder carbons), organic polymer, and organic and inorganic composite polymers, and the like. As specific examples of such materials to be dispersed, compounds as set forth in, e.g., Research Disclosure No. 17,643, No. 18,716, and No. 307,105 can be exemplified.
The dispersant according to the invention is suitable particularly for dispersion of water-insoluble photographic solid particles used for silver halide photographic photosensitive materials. The dispersant according to the invention is suitably used for dispersing water-insoluble photographic solid particles in a form of fine grains in a silver halide photographic photosensitive material having, on a support, at least one layer containing photosensitive silver halide, and at least one layer of hydrophilic colloids including water-insoluble photographic solid grains.
In the invention, the silver halide photographic photosensitive material can be, in addition to ordinary silver halide photographic photosensitive materials, photothermographic materials. For systems of the photothermographic materials and details of such photothermographic materials, Japanese Patent Publication (KOKOKU) Heisei No. 3-10,391, Japanese Patent Publication (KOKOKU) Heisei No. 6-52,387, Japanese Unexamined Patent Publication (KOKAI) Heisei, No. 5-341,432, Japanese Unexamined Patent Publication (KOKAX) Heisei, No. 6-194,781, Japanese Unexamined Patent Publication (KOKAI) Heisei, No. 7-13,295, Japanese Unexamined Patent Publication (KOKAI) Heisei, No.10-221,808, Japanese Unexamined Patent Publication ((OKAI) Heisei, No. 10-288,23, Japanese Unexamined Patent Publication (KOKAI) Heisei, No10-339,934, U.S. Pat. No. 5,380,635, and the like can be referred.
With such a photothermographic material, as water-insoluble photographic solid grains that can be dispersed in a solid form by the invented dispersant, exemplified are a reducing agent, an organic acid salt, a nucleation agent, a toning agent, a torning improving agent, a fog preventing agent, various dyes or pigments added for prevention of irradiation, and the like.
As a silver halide photographic photosensitive material to which the dispersant of the invention is applicable, a color reversal film, and a color negative film can be exemplified. Particularly, a general color negative film is preferred.
As a silver halide emulsion for producing the silver halide photographic photosensitive material, what is used is generally subject to physical ripening, chemical ripening, and color sensitizing. The advantages of the invention can be remarkably found when an emulsion more sensitized with a gold compound and a sulfur containing compound Additives used in such a process and known additives for photography that can be used in this invention are set forth in Research Disclosure No. 17,643, and No. 18,716, and the followings are posted locations.
The solid grains for photography dispersed in a solid form by the dispersant of the invention can be built-in at an arbitrary position of the silver halide photographic photosensitive material in an arbitrary amount according to the object. That is, the grains can be included in an undercoating layer, an anti-halation layer placed between a silver halide containing layer and a support, the silver halide containing layer, a yellow filter layer, an intermediate layer, a protection layer, a back layer located on the opposite side to the silver halide containing layer with respect to the support, and other assisting layers. It is preferable to be included in a hydrophilic collide layer, inter alia, more preferably, in a non-photosensitive layer, and further preferably, in a yellow filter layer.
The dispersant of the invention can be added not only in a single layer but also in multiple layers when necessary, and the dispersants of two or more types can be used independently or as a mixture in a single layer or multiple layers.
As hydrophilic colloids used in a photographic constitutive layer to which the dispersant of the invention is suitably applicable, gelatins are most preferable, and know various gelatins can be used. For example, gelatins made by different manufacturing methods, such as lime processed gelatin, acid processed gelatin, and the like, and gelatins chemically modified such as subjecting to phthalation or sulfonylation can be used. Moreover, the gelatins can be used upon desalting when necessary.
The dispersant of the invention is preferably used for dispersion of dyes in the silver halide photographic photosensitive material. The dye is preferably contained in a hydrophilic colloide layer made of a gelatin or gelatins. The use amount of the dyes may vary depending on kinds of used dyes, dispersion degree, necessary absorbance, and gelatin amount to be used. From a ratio to the gelatins, a range from 1/103 to 1/3 is preferable, and a range that optical concentration is 0.05 to 3.0 is preferable. The specific use amount of the dyes, though may vary depending on the dyes, is in general, 10xe2x88x923 g/m2 to 3.0 g/m2, and particularly, a range between 10xe2x88x923 g/m2 to 1.0 g/m2 is preferable.
The dyes dispersed by the dispersant of the invention can be used, when necessary, in combination with other various water-soluble dyes, water-soluble dyes adsorbed to mordant, dyes dispersed in an emulsion, and dispersed solid dyes manufactured by a method other than the method of the invention.
The dispersant of the invention is desirably used particularly for dispersion of the dyes represented by formula (II).
In formula, A represents an acid nucleus. The acid nucleus is not especially limited as long as it has an electrically negative ring structure, but preferably, it has more than one carbonyl group, for example, 5-pyrazolone, isoxazolone, barbituric acid, thiobarbituric acid, pyrazolopyridone, rhodamine, hydantoin, thiohydantoin, oxazolizindione, pyrazolizindione, indadione, hydroxypyridone, 1,2,3,4-tetrahydroquinoline-2, 4-dione, and 3-oxo-2, 3-dihydrcbenzo[d]thiophene-1, and 1-dioxide, and preferably, 5-pyrazolone, hydroxypyridone, pyrazolopyridone, barbituric acid and isoxazolone, and more preferably, 5-pyrazolone.
L1, L2, and L3 each independently represents a methine group which may be substituted. As a substituent of the methine group, for example, alkyl groups such as a methyl group, an ethyl group or the like, a cyano group, and a halogen atom such as a chloric atom or the like are raised. Preferably, L1, L2, and L3 are non-substituted methine groups.
R1, R2, and R3 each independently represents a hydrogen atom or a substitutent. As for the substituents shown as R1, R2, and R3, for example, a substituted or non-substituted alkyl group having 1 to 8 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, cyclohexyl, methoxyethyl, ethoxyethyl, ethoxycarbonylmethyl, ethoxycarbonylethyl, cyanoethyl, diethylaminoethyl, hydroxyethyl, chloroethyl, acetoxyethyl or the like), a substituted or non-substituted aralkyl group having 7 to 12 carbon atoms (e.g., benzyl, 2-carboxybenzyl or the like), a substituted or non-substituted aryl group having 6 to 18 carbon atoms (e.g., phenyl, 4-methylphenyl, 4-methoxylphenyl, 4-carboxyphenyl, 3,5-dicarboxyphenyl or the like), a substituted or non-substituted acyl group having 2 to 6 carbon atoms (e.g., acetyl, propionyl, butanoil, chloroacetyl or the like), a substituted or non-substituted sulfonyl group having 1 to 8 carbon atoms (e.g., methane sulfonyl, p-toluene sultonyl or the like), alkoxycarbonyl group having 2 to 6 carbon atoms (e.g., methoxycarbonyl, ethoxycarbonyl or the like), a substituted or non-substituted aryloxycarbonyl group having 7 to 12 carbon atoms (e.g., phenoxycarbonyl, 4-methylphenoxycarbonyl, 4-methoxyphenoxycarbonyl or the like), a substituted or non-substituted alkoxyl group having 1 to 4 carbon atoms (e.g., methoxy, ethoxy, n-butoxy, methoxyethoxy or the like), a substituted or non-substituted aryloxy group having 6 to 10 carbon atoms (e.g., phenoxy, 4-methoxyphenoxy or the like), a substituted or non-substituted acyloxy group having 2 to 8 carbon atoms (e.g., acetoxy, ethylcarbonyloxy, cyclohexylcarbonyloxy, benzoyloxy, chloroacetyloxy or the like), a substituted or non-substituted sulfonyloxy group having 1 to 6 carbon atoms (e.g., methanesulfonyloxy or the like), a carbamoyloxy group having 2 to 8 carbon atoms (e.g-, methylcarbamoyloxy, diethylcarbamoyloxy or the like), a substituted or non-substituted amino group or imino group having 8 or less carbon atoms (e.g, non-substituted amino, methyl amino, dimethyl amino, diethyl amino, phenyl amino, methoxyphenyl amino, chlorophenyl amino, morpholino, piperidino, pyrrolidino, pyridyl amino, methoxycarbonyl amino, n-butoxycarbonyl amino, phenoxycarbonyl amino, methylcarbamoyl amino, phenyl carbamoyl amino, acetyl amino, ethylcarbonyl amino, cyclohexylcarbonyl amino, benzoyl amino, chloroacetyl amino, methyl sulfonyl amino or the like), a substituted or non-substituted carbamoyl group having 1 to 8 carbon atoms (e.g., non-substituted carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl, t-butylcarbamoyl, dimethylcarbamoyl, morpholinocarbamoyl, pyrrclidinocarbamoyl or the like), a substituted or non-substituted sulfonamide group having 1 to 8 carbon atoms (e.g., methanesulfonamide, p-toluenesulfonamid or the like), a halogen atom (e.g., fluorine, chlorine, bromine or the like), hydroxyl group, nitro group, cyano group, and carboxyl group are raised.
R1 is preferably a hydrogen atom, an alkyl group, an aryl group, an alkoxycarbonyl group, or an aryloxycarbonyl group, but more preferably, a hydrogen atom.
R2 is preferably an alkyl group, an aryl group, an amino group, an alkoxy group, an acyloxy group, a carbamoyl group, a halogen atom, a nitro group, or a carboxyl group.
R3 is preferably a hydrogen atom, an alkyl group, or an aryl group, but more preferably a hydrogen atom or an alkyl group, and further preferably, an alkyl group.
n denotes 0 or 1, but preferably 0.
m denotes an integer from 0 to 4, but preferably, 0, 1, or 2, and more preferably 0. A plurality of R2 can be the same to or the different from one another when m denotes an integer of 2 to 4.
X denotes an electron withdrawing group having a Hammett""s sigma value "sgr"m of 0.3 to 1.5. The Hammett""s sigma value "sgr"m is described, for example, in Chem. Rev., 91,165 (1991). As an electron withdrawing group having a Hammett""s substituent constant "sgr"m of 0.3 to 1.5, followings are raised, for example, a Halogen atom (e.g., a fluorine atom ("sgr"m=0.34; the same unit used in followings), a chlorine atom (0.37), a bromine atom (0.39), an iodine atom (0.35)), a trifluoro methyl group (0.43), a cyano group (0.56), a formyl group (0.35), an acyl group (e.g., acetyl (0.38)), an acyloxy group (e.g., acetoxy (0.39)), a carboxyl group (0.37), an alkoxycarbonyl group (e.g., methoxycarbonyl (0.37)), an arylcarbonyl group (e.g., a phenylcarbonyl group (0.34)), an aryloxycarbonyl group (e.g., phenoxycarbonyl (0.37)), an alkylcarbamoyl group (e.g., methylcarbamoyl (0.35)), a nitro group (0.71), an arkylsulfinyl group (e.g., methylsulfinyl (0.52)), an arkylsulfonyl group (e.g., methylsulfonyl (0.60)), a sulfamoyl group (0.53) or the like, preferably an alkoxycarbonyl group, a cyano group or an arylcarbonyl group and more preferably an alkoxycarbonyl group or a cyano group and further preferably, an alkoxycarbonyl group.
As for the dye shown in formula (II), it is preferable that A is 5-pyrazolone, hydroxypyridone, pyrazolopyridone, barbituric acid or isoxazolone; n is 0; m is 0; R1 is a hydrogen atom, R3 is a hydrogen atom or alkyl group; and X is alkoxycarbonyl group or cyano group, and it is more preferable that A is 5-pyrazolone; n is 0; m is 0; R1 is a hydrogen atom, R3 is an alkyl group; and X is an alkoxycarbonyl group.
The dye represented by formula (II) is exemplified as follows, but the dye to be dispersed as a dispersant according to the present invention is not limited to this example. 
As described above, a novel polymer provided by this invention is useful as a dispersant. In addition, the dispersant of the invention does not suffer from lowering surface tension of dispersing material, and such problems rarely happen as deterioration of coating property along with degradation of surface tension caused by using a low molecular surfactant, diffuse transfer inside a hydrophilic colloid layer, and, in some cases, adversely effect on photographic performance. Also, the novel polymer has high dispersing ability and high dispersion stability, and when the polymer is used as a dispersant for a silver halide photographic photosensitive material, there provided high fixation rate to the inside of the structure layer in coating a hydrophilic colloid layer containing dispersing solids since solubilization property is low in a water-insoluble photographic usable compound. The silver halide photographic photosensitive material according to the invention excels in color reproducibility, and storability and latent image storability before use are concurrently improved.